2

I recently tried to replace an sealed cartridge bottom bracket with a threaded hollowtech system. In the process I shredded one of the threads and can't get the hollowtech cup in. After some study I noticed pressfit bottom brackets are compatible with hollowtech. Is it possible to install a pressfit BB into a threaded frame?

4

You can't put a pressfit bottom bracket in a frame not designed for pressfit bottom brackets.

Your best options are:

  1. Taking the bike to a bike shop and seeing if the threads can be salvaged
  2. Use an universal threadless bottom bracket like the Velo Orange Grand Cru threadless bottom bracket. And buy a square taper-compatible crankset.
  3. Follow this question's advice.
  • Thank you that is all I wanted to know. I was aware of salvaging the threads (it is not terrible, I think the threaded hollowtech cups actually took most of the damage) or going universal threadless. – Douglas Kastle Dec 16 '16 at 20:50
  • @DouglasKastle - Usually if you don't cross thread it too bad (i.e. you cross thread a bit, but stop; not force the thing on), things are salvagable. If you look at the threads, you might have an idea, but you may need to do some cleaning up or whatever. – Batman Dec 16 '16 at 22:50
1

Its WAY cheaper and arguably easier to get a shop to re-face and tap your Bottom Bracket shell than to get the Velo-Orange BB--though its a VERY cool product that every shop ought to have!-- and a new set of cranks. If you're good with threads, you CAN chase the threads, I'd try to install the "good" Hollowtech cup first, slide the bb spindle all the way through, then carefully try to rethread the damaged cup using the spindle as sort of a guide. Try to find the opening of the original thread and match it with the bb cup's starting thread.

In a pinch, if its the non-drive-side and the old cartridge bb uses a plastic retainer type sleeve that threads in, you could force that back in. It'll damage the plastic threads but it'll do its job of keeping the bb in place, even if it follows the "new threads." I'd be VERY surprised if that vibrates out! LBS might even have one off a throwaway, but I I've never tried to mix match, so I don't know if they'll fit any cartridge bb.

They DO exist, but the only proof I've found is an ended ebay auction from a year and a half ago, likely discontinued by YST. If you contact the seller, you might find out where they got them or if they have more, but I doubt they'll show up on the market before next fall..

  • I just realized you said the Hollowtech cup is probably damaged more than the frame. I'd TRY to clean up and chase the shell with the old bb, but only if it goes in easy-ish, then clean up the Hollowtech cup with something like a flat head before trying to re-thread it. – Mark Dec 17 '16 at 6:02
  • Hi Mark, thanks for the follow up reply. While it isn't the answer to the question, what you have suggested is exactly what I'll end up doing. I think the frame was damaged on the non drive side, and yes where I was having the issue, and the plastic retainer provides enough flex to be threaded whereas there is no give with the aluminum cups. I was successful in re attaching the old BB, I going to get a new one and hopefully get the same result. – Douglas Kastle Dec 17 '16 at 9:54

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.